Although chemical reactions, especially reactions of chemicals in an aqueous solution, have been investigated for many years, the reactions performed are not necessarily simple even when reacting pure chemical substances together, and especially when one or more chemical substance is a weak electrolyte. It is not easy to analyze such reactions correctly.
In an industrial process, since there are often impurities present, this problem becomes still more complicated. OLI Systems, Inc., at which one of the Inventors works, has been tackling this problem for many years, and has proposed that it should be possible to calculate thermodynamic properties for all substances having known species by using a program and support data base with a computer. In this computer system, the amount of species in the aqueous solution at a thermodynamic equilibrium state can be calculated. Chemical processes or devices are designed using this calculation result.
Process control details and control results are often manipulated, displayed and recorded using a “Distributed Control System (DCS).” However, software is specific to system manufacturers, hardware may also be specific, and it is difficult to link up with other systems.